


Lycan't Help Myself

by Pokey



Series: The New Wolfrisk Movies [3]
Category: Undertale (Video Game)
Genre: Chara has female genitalia, Consensual Underage Sex, F/M, Fluff, Frisk has male genitalia, Frisk is in heat, Frisk is precious, It's finally overtaken the main story in terms of views, Mating Cycles/In Heat, Nonbinary Chara and Frisk, Other, Saints preserve me what have I done, Smut, We're all thirsty sons of guns, Were-Creatures, aren't we, charisk, plz comment
Language: English
Status: Completed
Published: 2017-07-11
Updated: 2017-07-11
Packaged: 2018-11-30 23:15:41
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 4,572
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11473704
Author URL: https://archiveofourown.org/users/Pokey/pseuds/Pokey
Summary: Since becoming a teenager, poor Frisk has unknowingly started having heat cycles. It isn't until Chara has an anxiety attack during one of these cycles that Frisk figures out what the best source of relief is.[Part of the Werewolf Frisk AU.]





	Lycan't Help Myself

**Author's Note:**

> Took a break from writing the main story.
> 
> I hope to God my mother doesn't see this.
> 
> EDIT: Oh snap, I updated it. There's an epilogue now, taking place sometime in the middle of the night.

Frisk was going to be celebrating their fifteenth birthday, which _also_ happened to be the eve of the 5th anniversary of the barrier being destroyed, in less than a week. They still remember when they were officially adopted.  
  
About a week after they'd left the mountain, Toriel had asked Frisk when their birthday was, and they didn't know. That led to a search for a birth certificate, and when that didn't turn up anything, any other legal information on them they could find. Unfortunately, the search turned up absolutely nothing, so they had to work from the ground up. Toriel said that they were gonna have new stuff made for them, and so she asked when their birthday was going to be celebrated, if nothing else. After a few minutes of consideration, they decided that they wanted their birthday to be the day Toriel found them, because that's when they felt their life truly began-- Chara had rolled their eyes and groaned in exasperation when they heard that, but Toriel clearly hadn't found it as cringey as they did, because a few weeks later, they were presented with new identification papers that all listed that fateful day under 'birthday'. (Unfortunately, with a new life comes new responsibility: they also had to get their 'shots', but they were relieved when they were told it did not involve a pistol duel.)  
  
Presently, Frisk is lying on their bed, staring at the ceiling, waiting for sleep to come. They have the covers thrown back, because the dang things had some kind of inlaid quality that kept the heat in, which made no sense given how thin the sheets were.  
   They know that, if they're not going to fall asleep any time soon, they should be thinking about what they're going to do for their birthday, but they can't get over this weird sensation that's been affecting them. This wouldn't be the first time this feeling has sprung up--they're pretty sure it's been happening in a pattern.  
   It felt like they were burning up constantly, with the occasional tingling sensation popping up in various parts of their body. It always felt like a fever, and it always lasted way too long for their taste. However, there was one good thing about it: sometimes, certain things would happen in their presence that made them feel... different.

Usually these events involved Chara to some capacity--one time, Chara was stretching to work a kink out of their back, and their sweater lifted partially, exposing their taut midriff. Frisk didn't know why that made them feel the way it did, but that was just one of many events that led them to believe it was connected to their attraction to Chara.  
   They could be a real jerk sometimes, but they were really smart... and cool... and funny... and they _always_ made them feel better when they were sad. For this, Frisk was thankful, and so they repay them by always being available for a specific thing. Chara would sometimes go into fits of panic or anxiety, and afterwards they'd want to rest their head on Frisk's thigh, for the purpose of getting Frisk to stroke their hair, just like at the MTT hotel all those years ago--it always happened if it was an attack, but sometimes they'd do it just because. (Thinking about stroking their silky auburn hair right now made the weird feeling come back. Dang it.) Chara said they liked it even more when there was a Full Moon in the sky, because "bigger hands mean more coverage, ergo, more scratchin's."  
  
They're roused from their thoughts by a very distressed-looking Chara--speak of the devil--opening the bedroom door, walking over to the bed, and resting their head on Frisk's stomach.

They used to be the only one that could see or hear Chara, and, when they got killed by Muffet, they could add 'feel' to the list. However, at the time, it was limited to weight and pressure sensitivity--texture was still a bit beyond what their ghostly form was capable of. About two years ago, though, they found a way to give Chara a real body again (thank you, Yahoo Asks), and now, they've gotten to grow up together.

Of course, that brings them to the awkward position of having their crush's body heat pressed against them--crushing them, if you will-- begging their attention. They begin to pet the distressed little demon (well, they say 'little', but, being a couple of years older, Chara usually was rather tall compared to them, most of the time), as per usual, and Chara releases the breath they'd been holding at the contact. Frisk can't really enjoy it as much as they know they normally would, because this... thing... is causing their thoughts to get all muggy.  
  
The added heat is not helping, either.  
  
"...Chara?"  
  
"Yes?"  
  
"I want to keep petting you, I really do, but I was burning up _before_ I had a toasty human lying on me. 'Can't think straight." Chara lifts their head off Frisk's stomach to look at them, and taps into their connection with Frisk's soul to check their status.

"That...doesn't make any sense. You're not sick, or feverish, or anything. And it's not the environment doing this either. This is... strange, to say the least."  
  
"And, um. If..." Frisk curls their fingers a couple of times. "If it will help you figure out what's wrong with me..." They duck their head. "When I feel all hot like this, thinking about you makes me... feel funny," they murmur, bashfully. They're blushing and refraining from making eye contact, which just makes Chara even more perturbed. They shift on the bed to support themselves on their arm.

"Um...like, 'strange' funny?" They stare wide-eyed at Frisk--in this moment, they're filled with a more rational concern for what they think might be coming next, which just piled onto the butterflies they already had (the whole reason this whole mess started), which made for a stressful combination.  
  
"No, like...'good' funny," they mumble, sheepishly, beginning to fiddle with their fingers. Oh, dear.  
  
"Frisk..."  
  
"You make me feel nice inside. You're really cool, and you know a lot of things about a lot of things, and, and...

"I think you're really pretty," they say, looking off to the side, their voice clipped and tight. Oh, no, this isn't your everyday Frisk flirting (trademark). This is them opening up to Chara, telling them how they feel. And Chara's on top of them.

Chara's mouth goes tight-lipped. Their face turns beet red as they realize how their position might look to an outsider.  
  
They quickly lift off of them and begin to walk towards the door.  
  
"Chara," Frisk yells to them, suddenly sounding despaired. Chara stops and turns back around. The kid's sitting upright, looking at them with tears already beginning to prick the corner of their eyes. Chara mentally kicks themself. They stride back over to the bed and reach over, hugging Frisk tightly.  
  
"I should've--" they start, immediately hugging them back, curling their fingers into Chara's sweater and leaning against their sturdy body. They immediately regret inhaling, as they immediately pick up their scent, and it makes Frisk's whole body _burn_ with a yearning for their friend, but all they can do is grip them tighter and feel their heart break, and so they stare off into space for a good few seconds, their eyes glistening more with the crushing feeling of loss beginning to set in.  
  
"...I'm sorry." They whimper quietly, little raspy voice not at all even, and Chara realizes that they're taking this harder than they thought.  
  
"Wait.. hold on-- you didn't do anything _wrong_ , kid. I jussst can't handle people telling me serious things like that very well, is all..." They back out of the hug to look at them-- their lip still wobbles a bit, but they've a little glimmer of hope in their eye now.  
  
"Now, then, about how you're feeling...  
  
"Er..." Their face heats up again. "Based on what you're feeling, coupled with your apparent... attraction to me, and your more... monstrous qualities, I'm under the impression that you may be... in heat," they say, wincing. Frisk tilts their head in confusion.  
  
"I guess that makes sense. It  _does_  feel like I'm burning up," they say, voice evening out. Chara chuckles warmly.  
  
"No, that's not quite what that means." Their smile fades back into a nervous, thin line. "I don't think humans are supposed to get these, and it's usually monsters that experience _this_ kind, but you're not entirely human, so I don't know." They sigh. They're really going to have to explain this. "Your body is trying to tell you it wants to... make babies." Frisk raises their eyebrows. "...and, in... order to do that, one must... engage in... intercourse with a member of the opposite sex," they say, not daring to look the kid in the eye.  
  
"Can you show me how," they ask, bringing a hand to their chin. Chara's head snaps to attention, an incredulous look on their face, but looking at the kid's expression, they can see there's innocent curiosity in those eyes.  
  
"Uhhhh..." Chara's face starts glowing as they think about what that would entail.  
  
"Please, Chara, I wanna make this stupid 'heat' go away," they plead, taking Chara's hand in their own. Chara gazes down at said hand, eyes still wide as saucers, and exhale sharply. They move their gaze to the kid's frowning face, and sigh heavily.  
  
"I'm going to regret this, I'm sure," they say, weaving their fingers together with Frisk's--their heartbeat quickens--and gently lower Frisk's head back onto the pillow.

"What are you doing?" They look confused... worried, a bit.

"I... I'm going to show you how it's done, yes?" 

Frisk immediately feels a smile breaking their neutral expression.

Chara looks down at them from their perch on their knees, eyeing the kid's torso between their legs. They look back to the kid's glorious, emerald green eyes, how they're filled with nothing but love and admiration. They're cute.

They scoot back towards the foot of the bed, and gently untangle their fingers from Frisk's. Chara gulps, and slowly moves from the kid's hand to the top button of their shorts.

"Here we go," they say, quietly, and undo Frisk's top button with a quiet, metal pop.

\---

Chara motions for Frisk to lift their legs up a little bit, and, ever so gently, begins to pull Frisk's shorts down. Frisk lifts their head, supporting themself on their right elbow, and they watch Chara nimbly shimmy their shorts down their legs with bated breath. Chara pauses to look them in the eye, silently asking for permission. When Frisk doesn't say anything, Chara lifts their feet up off the bed, and pulls the shorts off the rest of the way. Chara looks up at Frisk again, who's now down to just a sweater and underwear, and exhales.  
  
"Are you sure you want your first time to be with me, of all people," Chara asks, and Frisk nods enthusiastically, grinning with a mouth full of sharper-than-average teeth; Chara briefly wonders what it'd be like to have those teeth press down on their neck.  
  
Frisk's gaze follows Chara's hands as they move back up to their waistline, shimmying their pointer fingers under the hem of Frisk's underwear to get a good grip, and lightly graze Frisk's skin -- they shiver in anticipation at the contact.  
  
Chara begins to pull down their underwear, slowly, with the same amount of caution as before. Frisk grips the pillow tightly, drawing a sharp breath of surprise as their cock slowly begins to peek out from under the fabric. Chara pauses to look at Frisk's stiff member, then at their face--they simultaneously look nervous and ecstatic.  
  
They pull the underwear down Frisk's legs the rest of the way, and lightly toss it aside. They continue to sit on their knees, with the kid's shins between their legs, and begin to lift their sweater.  
  
"Wait!" This breaks Chara's concentration, and they let go of it. Frisk relaxes, and lays back down.  
  
"What's wrong?"  
  
"I--'ve... for a while now... I don't know why, but I wanna..." They pause, going into a whisper. "S-see your chest. But if your sweater's finally coming off,  _I_ wanna take it off. Plus, it's not fair if you have to do everything," they say, voice slowly returning to normal volume.  
  
"Okay...if you say so..." Chara says, somewhat sarcastically, and slowly lower themselves forward, down onto Frisk's chest. They can feel their breath, warm and moist. Frisk winces as Chara lowers themself onto them--their cock is being squished between the two. It twitches, and scrapes against Chara's sweater. Frisk quietly groans, and looks at Chara with lidded eyes full of love and need.  
  
"Chara..." They moan. Chara's face becomes even redder. "I need you..." Frisk lightly pushes them up, and grabs at the hem of their sweater, beginning to lift it up. Chara squeaks when they feel the fabric leave their midriff, exposing it to the air, cool and dry, in contrast to their body, which had heated up considerably in the last few minutes.  
   Frisk pauses at the base of their arms, still breathing heavily, and Chara starts to nervously shift in place, feeling a little shy, but they quickly stop when it elicits a sharp sound of pleasure from Frisk. Chara blinks, starting to become aroused as well, strange, hot neediness beginning to flare up between their thighs. They give, and lift their arms up, allowing Frisk to pull their sweater over their head.  
   Chara brings their right arm to cover their chest, watching Frisk toss their sweater aside. Frisk brings their attention back to Chara, and their gaze slowly moves from their fiery crimson eyes, to their soft lips, to their small, soft breasts, following the subtle curves of their torso.  
   Frisk lightly grasps Chara's right arm, gently pulling it away from their chest, bringing their body back down to rest against Frisk's sweater. Chara's breath hitches when their nipples scrape against the fabric, and Frisk's stiffened member twitches at the sound. The two of them lay there, together, breathing heavily as they looked into each other's eyes. What even are they anymore? Lovers? Partners?  
  
Chara quietly yelps as Frisk places an ice cold hand on the small of their back, and another between their shoulder blades, lightly smoothing the skin over, getting a feel for them. "Chara," they breathe. "Can I take your pants off?" Frisk doesn't quite get what's happening, but thinking about the tall, pale senior's body, whatever lies behind Chara's tight leggings... it's making their weiner hurt so bad, but _why_? Why, why, _why_ , though? They need to, like, touch, squeeze it, maybe,  _put_ it in something, but what? And again: Why?

Chara gulps, and a smile creeps onto their face. "Okay," they whisper, excitedly. Frisk can feel their balls tighten at their tone of voice, and bits of precome begin to bead up. Chara brings their knees closer together, and inches closer to Frisk to make it easier for them. They grab at the belt loops of Chara's chocolate-colored shorts, and pull the shorts down their legs in one swift movement. As the shorts approach their feet, Chara lifts either leg to free their foot. They're bent over slightly, bringing prominence to the subtle curvature of their breasts. When they've freed the second foot, they look back up at Frisk with lidded eyes and a sly smile.  
  
Frisk's erection starts to throb, leaking precome all down the shaft--their heart is racing as Chara affixes a hand around the waist of their leggings, pressing their thumb down into the garment. Their breathing must've picked up, too, because Chara's sly smile becomes a smug grin. Let's see how much they can stand.  
   Frisk makes a small whine, and their dick pulses when their super doggy ears pick up the sound of Chara's thumb scraping the inside of their pants, when they see Chara lick their lips seductively, squishing their breasts between their biceps. Frisk quietly groans, but they still don't know why. They find their hand slowly drifting to their aching cock, desperate for relief. Chara quickly drops the act, and grabs Frisk's wrist before it can get anywhere--they don't need the kid picking up bad habits just because they started feeling comfortable enough to be an ass to them.  
  
They finally start pulling the tights down their legs--they close their eyes, exhaling loudly through their open mouth as the wet, aching thing between their legs comes into contact with the air. After they get used to it, they slowly climb back onto Frisk's chest, bringing their exposed crotch to rest on Frisk's stomach. Frisk watches Chara's belly rise and fall, and, looking up into their eyes, their heart sings; perhaps the "why" doesn't really matter. But the "who" -- the little 'demon' whom their heart had long since started aching for -- matters way more. They want to make Chara feel not sad  _all_ the time, and from the way their skin started glowing red in some places, they're probably feeling a lot like Frisk right now. They steel their resolve.

"Are you ready?"

"Yeah." They are determined.

"Okay," they breathe. Their muscles tense when Frisk lightly grabs at their thighs, hoping to adjust their position on the bed. They're sat down again on top of Frisk's pelvis by coincidence. They can feel their butt pressed up against Frisk's cock; they can feel them throbbing, wet with need.  
  
"Now, Frisk, I'm going to...lower myself onto you," they say, absent-mindedly pulling at the hem of Frisk's sweater, pushing it upward. They adjust their position, and promptly lean forward, pressing their breasts into Frisk's exposed chest. "When I do, it's going to hurt a little, at first. But it'll make us both feel...so good..." Chara whispers, ghosting their fingers along Frisk's own curves (which have been slowly turning plump and voluptuous as the child grows), rubbing their entrance up against Frisk's burning shaft. Frisk whimpers, squeezing their eyes shut. They quickly nod, biting their lower lip.  
  
Chara slowly lowers themself towards Frisk's cock, finally. They can feel it begin to press against their entrance, prepped to push into them. Frisk opens their mouth to say something, but it comes out as a whine. They need to tell them this, though, so they try again.  
  
"I... I l-love you," they stutter as Chara lowers onto them, taking their entire length easily. Chara roughly grips Frisk's forearms and doubles over. They suddenly feel Frisk's heartbeat, hot and throbbing within them, sending shocks all up their body-- it's nearly too much, at first.  
  
"Hah~" They shiver in place, letting the initial shock pass, feeling it's electricity course through their belly. After a moment, they begin to move up and down, ever so slowly, producing smaller, more pleasurable shocks. Quiet, slick sounds start to be heard coming from between them, and Chara's breathing slowly starts to get louder.  
  
"Oh... ooh~..." Frisk groans, lightly lolling their head back.  
  
"Chara... I--ahn..." Frisk reaches to take Chara's hand, and Chara accepts it, nearly crushing it in their grip.  
  
"Hah... hah..." Chara's stomach muscles are tensed. They can feel a coil beginning to tighten in their belly, and it feels amazing.  
  
"Hoh... hahn~...Don't stop," Frisk whimpers. Chara's thrusting has picked up, and they lean their head over Frisk's shoulder, in a tight embrace.  
  
"Hhhn--ah! Chara, ohh~" They moan, a lump forming in their throat. They nip at Chara's ear, lightly sucking on their ear lobe, moaning into their ear with their eyes closed.  
  
"Gahh... hahh!..." Chara squeezes their eyes shut and bares their teeth; they can feel Frisk throbbing within them, eagerly bobbing in and out, searing their sensitive flesh with their modest girth. They press their head against the shorter child's shoulder, passionately planting breathy kisses all along Frisk's neck. They feel serene, almost, alone with them.  
  
"Chara... Chara!..." Frisk yells, wrapping their arms around Chara's back. They've begun to pick up speed, and it hurts. Their dick feels like somebody's stabbing through it with a spear. They gently knead Chara's back as their heart swells with affection. 

"I love you so much," they sob, wrapping their legs around Chara's torso, and begin noisily lapping at Chara's nipple, moaning as they feel their cock piston in and out of Chara's cozy, beautiful body.  
  
"Ah!... hah!..." Chara can feel that little coil in their stomach winding tighter and tighter with each passing moment. They start thrusting with more vigor than ever, groaning loudly as they wrap their arms ever tighter around Frisk's back. They ache for release but they want it to last forever it feels so good oh God, Frisk!  
  
"Oh, Chara!... ahh, hahn~!"

Chara starts grinding against Frisk's pelvis, trying desperately to soothe their aching clit. They want Frisk's red-hot cock to go deeper, deeper--their libido is raging. Frisk's toes curl up, and they grip Chara as tight as they can, their dick feels like it's about to snap in two, please Chara please don't stop!  
  
"Agh! ...Frisk! I... h-hahh!~" Chara groans, their tongue lolling out of their mouth.

Frisk's tongue, their horrible wonderful tongue! They're sucking and lapping at their nipples so vigorously, lingering just enough for short bursts of ecstasy as they _ravage_ them. Frisk, th-they're being so  _noisy!_  Frisk, keep going, please!  
  
"Chara!...I... _I..._ ohh~!" They sob into Chara's chest, suddenly, their voice rising in volume and pitch. Their muscles start convulsing in their euphoria. Something's about to come out of them, that scares them, they don't want it to end, oh Chara please stay!  
  
"Frisk, oh God you're so hot, I, I can't hold it! I..." they yell in distress. Their pussy's beginning to squeeze Frisk. Chara feels them stretching them, boiling them alive! They _ache_ for them! Please, Frisk, please?!

They lurch forward, screaming Frisk's name, shivering with ecstacy as their insides tighten around Frisk, getting tighter, and tighter, pulling them deeper, and deeper. Frisk's sweltering boyhood is thumping within them, balls taut with the need to fill them up. It feels so _good_...  
  
"I love you, Chara!" Frisk bawls. They can feel it coming...!

They cry out, and pull Chara into a bone-crushing grip as the floodgates open. Chara arches their back, yelps turning into moans as Frisk continues to pump up into them, seven... eight... nine times, filling Chara with all their love, bringing the lanky teenager over the top once more.

The two of them rock together, riding out each other's respective orgasms in a tight embrace. The kid is quietly sobbing as they lay there, but is not quite sure why, because they're so happy right now. They bury their head into the crook of Chara's neck, taking in a very shaky breath.  
  
"I love you so, so much," they say in a sad-sounding, watery voice.  
  
" _Mm~mph_... I suppose, I like you, as well," Chara replies, lifting a lightly shaking hand to Frisk's head, stroking their hair for a moment as they rest their own upon it. They know that if they weren't coming down from a pleasure high right now, it probably would've been a lot harder to say, but right now, Frisk is just too precious to ignore, they think as they caress their cheek.

They eventually climb off of Frisk, soliciting a sensual groan from them. Frisk's tan-colored pelvis has acquired a wet, sticky sheen, having been drenched in Chara's come--proof of ownership. Frisk's breathing still sounds like they just came from a funeral, but they're visibly very happy, which is what they deserve to be.  
  
Chara leans in towards Frisk, cupping their face with both hands, and presses their tongue into Frisk's mouth. Frisk makes a surprised noise at the sudden intrusion, but quickly wraps their arms and legs around Chara's naked body again, humming contentedly. A mixture of the two's come leaks out of Chara and onto their stomach, reminding them. It's real, it's finally _real_. They moan into Chara's mouth.  
  
The two eventually back out of the kiss, and stare each other down, panting heavily. Chara smiles, and quietly laughs. Frisk pushes their hair behind their ear, and grins eagerly. They pause, though, looking a bit sheepish.  
  
"My teeth didn't hurt you, did they?" They ask, nervously, prodding at one of their sharper-than-average pearly whites.  
  
"Not at all. In fact, I'm considering going in for more," they say, staring at Frisk hungrily. Surprisingly, Frisk was a _very_ good kisser, and they retroactively felt bad for themself for not finding this out sooner. They lean back in, kissing Frisk greedily for about ten straight seconds. Chara, partially removing their mouth, mumbles something to Frisk before diving back in. They're rewarded with Frisk going stiff again. They promptly back out of the kiss, look down at the newly formed erection, then look back at Frisk, who goes red in the face.  
  
"I-it's okay. You don't have to do it again if you don't want to. ...You were just showing me how it works, after all." They look a bit crestfallen.

Chara narrows their eyes, and, all without breaking eye contact, grabs Frisk's rod and lowers themself onto it with a wet slap, silently welcoming back the warmth it brings. Frisk's breath hitches. With love in their eyes, they gaze up at Chara, who smugly grins back at them.

"Hh...happy birthday to me," they say, their voice full of awe. Chara laughs, and kisses their forehead.

\---

In the dead of night, Chara wakes up in a cold sweat, breathing heavily. They sit up, their knees against their chest, and begin to weep silently for reasons not even they know. God, they hate it. They just want to sleep...

A hand clutches at theirs. They look down to see Frisk, attempting to comfort them. Must've felt the weight of the bed shifting. They sigh, squeezing their hand right back. They always feel stupid when they're caught in a moment of weakness like this, but they can trust Frisk. Chara lies back down, and shimmies in closer to them, huddling together. Frisk pulls them in further, holding them close.

Their bare skin brushes up against Frisk, reminding them of what the two of them had done, over and over until passing out. Chara smiles, remembering how Frisk would make those cute little cries and whimpers, how lovely it felt to have Frisk's come spread through them, stinging their insides with tangy, golden fire. They sigh contentedly at the memory.

"...You know what's funny?" They whisper to Frisk, pulling the blanket back over the two of them.

"Hmm..." Their warm breath helps to heat Chara's chest.

"We didn't use any contraceptives," they chuckle.

"I don't know what those are, really, but if I did, I still wouldn't care. It was great the way it was," Frisk mumbles with surprising clarity.

They go still again, falling into a trend of soft, even breathing. Chara watches them for a while after that, contemplating their words, and how much they unknowingly helped Chara's self-esteem. Frisk looks very cute when they sleep, they think. As they begin to drift off again, they bring their arms and a leg around their friend's body, caressing the smaller adolescent. They hesitate, but begin to whisper;

"I love you."

**Author's Note:**

> I have signed my own death warrant.
> 
> Please leave a comment.
> 
> The "sequel":  
> http://archiveofourown.org/works/12041484/chapters/27263790
> 
> Assuming Toriel went in to check on them (you know, as you do), one can hope that they had the foresight to cover up with the blankets.


End file.
